While we have had some discussions about the validity of R' Tropper's approach, we have not really focused on the consequences.
R' Tropper is using geirus as a tool in kiruv. When he finds that a baal teshuva is stuck because he is married to a non-Jew he switches hats and works to have the non-Jew become a Jew. Thus he reasons it is a win win situation. The Jew becomes fully observant and his wife becomes Jewish. Their children now will add to the Jewish population instead of destroying it. The only down side, he reasons, is that the age old practice of not proselytizing needs to be bent a bit. Any problems with this he reasons are made up for by requiring the convert to adopt an Orthodox life style. Seem like a nice neat package. Why should anyone be upset with it.
Let us list the reasons.
1) He has removed the age old stigma to intermarriage. There is absolutely no consequences of intermarriage. If you ever want to legitimate it he is standing there with open arms. Of course since not all Jews want to be Orthodox - therefore he contributes to the intermarriage rate by allowing everyone to chose a non-Jewish partner without the slightest guilt or consequence. Consequences unknown. But we can reasonably assume that more Jews will intermarry with R' Tropper looking the other way - then will return to Judaism with a converted bride.
2) Let's assume that not everyone that R' Tropper converts will stay frum. Because he has such high standards and is makpid on kabbalos mitzvos - all of his converts will definitely become Jews. However the statistics from the past tell us that at least half will back slide. They will then become irreligious Jews. If he wasn't so meticulous then when the convert goes back they were never Jewish in the first place. If he wasn't so meticulous then the back sliding converts will be genuine non-Jews.
3) The consequences of having converts who are genuine Jews and were married in a genuine marriage - but who give up observance is very simple - mamzerim. Rav Moshe solved the mamzerus problem from the Reform and Conservative by saying their marriages were non valid. Similarly their converts are not valid. Not so R'Tropper's converts. However everyone of R' Tropper's converts is a potential producer of mamzerim.
4) An additional consequences in back sliding will be on the communities and families.
This is similar to the statement about Sedom. They had horrible laws - which weren't enforced until an honest judge Lot came along. It is specifically because he is makpid on keeping the laws that he is causing problems.
In sum. For R' Tropper to come along and introduce a change in the dynamic of the Jewish community he needs to show that what he is doing is beneficial. It is not enough to say that when he converts people they were frum. Rav Chaim Ozer had such a view and then 20 years later radically altered it to say that a decent beis din should not do conversions. Similarly Rav Moshe Feinstein knew all the hetirim but personally had nothing to do with geirus. What are the two, five and ten years statistics on Rabbi Troppers' converts. What is their impact on marriage and children?